Electrical instrument.



No. 798,063. PATENTED JUNE 27, 1905. J. J. GHEGAN.

ELECTRICAL INSTRUMENT.

APPLICATION FILED JAN. 27, 1904.

Patented June 27, 1905.

PATENT OFFICE.

JOHN J. GHEGAN, OF NEWARK, NEIV JERSEY.

ELECTRICAL INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 793,063, dated June 27,1905.

Application filed January 27, 1904. Serial No. 190,782.

1'0 all whom it may concern.-

Be it known that I, JOHN J. GHEGAN, a citizen of the United States, anda resident of Newark, Essex county, State of New Jersey, have inventedan Electrical Instrument, of which the following is a specification.

This invention relates to electrical instruments, and has for its objectto construct a device, such as a telegraph-relay, that will adjustitself to varying strengths of battery-current and will also respond tocomparatively slight changes in the resistance of its circuit.

On telegraph-lines of considerable length, even when battery strength isconstant, great difliculty is found in keeping the relays properlyadjusted, particularly in damp or wet weather, when leaks or escapes ofthe current occur from imperfect insulation. My invention overcomes thisdifficulty even when the leaks or escapes amount to over fifty per cent.of the line-current.

Another advantage gained by my invention is that when the key simplyadds a given resistance to the circuit instead of opening it, as isgenerally done, the leaving of the keyswitch open, accidentally orotherwise, does not necessarily leave the line open or unavailable, evenfor the oflice where such opening occurs, as on the working of any keyall relays immediately adjust themselves to the changed condition.

The principle upon which my invention is based is very simple and can beutilized in various ways, so that while I have shown but one adaptationI do not limit myself to the construction or arrangement shown.

My invention consists, broadly, of a movable armature, the extent oramplitude of its motion being governed by the strength of abattery-current and adapted under slight variations of current strengthto move correspondingly.

The accompanying drawing represents diagrammatically an arrangement oftelegraphic instruments illustrating one adaptation of my invention.

In this arrangement the relay comprises a magnet 1, preferably of thesolenoid type, with a sliding core 2. Satisfactory results may beobtained with the pivoted disk form of solenoid, such as used involtmeters; but it is not even essential to use a solenoid, as otherarrangements have proved available to obtain amovable armature theextent of motion of which is governed by the strength of thebattery-current. As shown, the core-tube 3 of the magnet 1 is extendedbeyond one end of the coils of the magnet, and each end of this tube isclosed or capped except for openings through which the extensions 4 and5 of core 2 pass to guide the core in its motions. Compression-springs 6and 7, bearing between the outer closed ends of tube 3, and stops 8 and9, secured to the rod extensions 4.- and 5, all respectively as shown,tend to maintain the core 2 in its normal position when no current ispassing through the coils. This core and its extensions constitute themovable armature to which I have referred. In order to cause themovements of the arma ture to operate a local sounder, I provide amovable contact or follower that will be automatically adjusted foroperation by slight movements of the armature in any position of thelatter given it by changes in the strength of current in the coils 1.There are various ways of obtaining such a contact; but in the drawing Ihave shown a preferred construction. A dash-pot 10, containing glycerinor any other suitable fluid, (or it may be an air dashpot,) is providedwith a piston 11 and rod 12, preferably of lighter specific gravity thanthe fluid in the dash-pot. The rod 12 has an insulated stop 13 and acontact-stop 14, between which stops the contact-point 15 of thecore-armature is arranged to play.

When a current is passing through the coils of magnetl, the core 2 isdrawn down, causing the contact-point 15 to press upon contact-stop 14:and force the piston 11 farther down into the dash-pot, the extent ofdownward motion corresponding to the strength of the current acting uponcore 2. If the current in coils 1 materially decreases or is cut off,the core 2 rises and its contact-point 15, pressing against theinsulated stop 13, forces the piston 11, and consequently thecontact-stop 14, upward. The piston 11 and rod 12 being of lighterspecific gravity than the fluid in the dash-pot 10 will gradually riseup until contact-stop 14 reaches contact-point 15 of the armature, so

I that the instrument is in readiness at all times for operation by theusual means of signaling. The dash-pot arrangement acts to retard themovements of thefollower-contact, and consequently to cushion the longeror extreme motions of the armature, thus preventing jerking of thearmature and its movable contact due to sudden material changes in thecurrent strength in coils 1. The coils of magnet 1 are connected up inthe main line of the telegraphic system, as with an ordinary relay.

In the drawing is represented a key 16, adapted to add a givenresistance 17 to the circuit when opened. The key-switch 18 is shown asleft open. The coils of the soundermagnet 19 are connected to themovable armature through wire'2O and to contact-stop 14 through wire 21,in which is shown alocal battery 22. The key is shown as inserted inline-wire 23, running to the magnet 1, the

other end of the coils of magnet 1 passing to the line-wire 24.

The operation of the device is as follows: Assuming the normal currentstrength to be on the line, when a key is operated, either to open thecircuit or to insert an additional resistance in the line, core2 willrise in response to the variation in current strength in coils 1. Thiswill break the contact at 14 15 and open the local circuit throughsounder-magnet 19. Upon the closing of the key core 2 is drawn downagain and contact is made at 14 15 and the local circuit throughsounder-magnet 19 again closed. Core 2 will respond to very slightchanges in current strength to make and break at 14 15, and although'thepiston 11, rod 12, and contact-stop 14 tend to rise when released bycontact-point 15 this rising motion takes place very slowly and does notinterfere with the operation described. Assuming that a key-switch 18has been left open by mistake, all the core-armatures along the linewill remain in the position corresponding to the reduced currentstrength of the main line and the movable contacts 14 will followcontacts 15, as described, so that when another key is operated thefurther reduction in the main-line current will act upon cores 2 to drawthem farther up and break contact at 14 15. If the key-switch is thenclosed, the added strength of current will force core 2, contacts 14 and15, and piston 11 all down again to their original positions. It will bequite evident that leakages will act upon the movable core-armatures inthe same manner as leaving key-switches open and putting in resistanceswill and that the relay will not cease to act unless the main-linecurrent becomes so Weak as not to affect the core 2.

I claim as my invention- 1. The combination of an electric circuit, anarmature adapted to shift its position according to the strength ofcurrent in said circuit,. and means for cushioning the movements of witha second electrical circuit and a movable 7 contact automaticallyadjustable to the varying positions of said armature, said contact andsaid armature being electrically connected to this second circuit andadapted to make and break it when the armature is vibrated.

2. The combination of an electrical circuit, an armature adapted toshift its position according to the strength of current in said circuit,and means for cushioning the movements of the armature when thuschanging its position to prevent recoil -or jerking, said armatureadapted to be vibrated in its various positions by signal impulses sentthrough the circuit, with a second electrical circuit and a movablecontact adapted to be adjusted by motion of said armature to a constantrelative operative position with the armature, said contact and saidarmature being electrically connected to this second circuit and adaptedto makeand break it when the armature is vibrated.

3. In a telegraphic system, a main line, a key for sending signals overthe main line, a local circuit, a solenoid connected up in the main lineand provided with an armature adapted to shift its position according tothe strength of current passing through the solenoid and means forcushioning themovements of the armature when thus changing its position,said armature adapted tobe vibrated by the operation of said key whilein various positions, and a movable contact'automatically adjustable tothe varying positions of said armature, said contact and said armaturebeing electrically connected tosaid local circuit, and adapted to makeand break it when said armature is vibrated.

4. The combination with an electric circuit, of a movable armature theextent of motion of which is governed by the strength of current in saidcircuit, and a dash-pot provided with a piston and piston-rod, a contactcarried by said piston-rod, said piston, rod and contact adapted to bemoved by said armature to adjust the said contact to the varyingpositions of said armature.

5. An electrical instrument comprising a tube, coils of wire surroundinga portion of said tube, a core movable within said tube and providedwith extensions, and caps on the ends of said tube, said capshavingopenings through which said extensions pass to guide and centersaid core in said tube.

In testimony whereofI have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN J. GHEGAN. Witnesses: MABELLE F. LAKE, EDITH J. GRIsWoLD.

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